v.发出嗡嗡声,哼唱( hum的现在分词 ),忙碌,活跃
The guard stopped his humming and turned his head sharply.
守卫停止了哼唱,猛地转过头。
There was a low humming sound in the sky.
空中传来一阵低沉的嗡嗡声。
Within five hours, the equipment will be humming away again.
用不了5小时,设备就又能嗡嗡地运转了。